Hymenoptera from Central America. 267 



and by having the first abdominal segment not petiolate 

 {cf. ' Ueber den systematischen Werth des Fliigelgeiiders bei 

 den Hymenopteren,' p. 23). 



From ISmith finding TrigonaJys hipiistulata in a nest of 

 Pollutes lam'o, it is probable that the genus is parasitic in 

 wasp nests {cf. Smith, Trans. Ent. Soc. Lond. i. (n. s.) 

 p. 176). 



The six species here described may be separated as 

 follows : — 



1 (2). Scutellum pyramidal, bifid at the top scutellaris. 



2 (1). Scutellum fiat, uot divided at the top. 



3 (4). Bodv yellow, marked with black ; second cubital 



cellule petiolate maculifrons. 



4 (9), Body black, marked with yellow ; second cubital 



cellule not petiolate. 



5 (6). Abdomen fulvous, banded with black apicipenjiis. 



6 (5). Abdomen black, narrowly banded with yellow . . Jiaouywtata. 



7 (8). Thorax with many yellow marks; the wings not 



smoky in frcnt. 



8 (7). Thorax with few yellow marks ; the wings broadly 



smoky in front fasciatipennis. 



9 (4). Body black, the petiole white : wings violaceous. . Championi. 



Trigonalys si:utellarisj sp. n. 



Nigra, postscutello maculisque 2 metanoti, tibiis tarsisque flavis ; 



alls fulvo-hyalinis. S - 

 Long. 10 millim. 



Hab. Mexico, Omilteme in Guerrero, 8000 feet (//. IT. 

 Smith). 



Antennae entirely black, covered with a short black micro- 

 scopic down ; the third joint distinctly shorter than the 

 fourth. Head impunctate, shining, densely covered, and the 

 mandibles also, with long dark fulvous hair, the mandibles 

 entirely black. Thorax densely covered with long dark 

 fulvous hair, above coarsely rugosely punctured ; postscu- 

 tellum pyramidal, yellow, depressed in the centre above, 

 making it bidentate ; the teeth blunt, rounded at tiie top; at 

 its sides the thorax is crenulated. Tiie median segment 

 coarsely reticulated, the apex in the middle coarsely trans- 

 versely striolated, its extreme apex being also crenuhited 

 behind the reticulated part ; the pleuras irregularly reticu- 

 lated, the base of the propleurae and the apex of the meso- 

 pleurae smooth, the raetapleuraj more strongly reticulated than 

 the mesopleurai. Abdomen shining, impunctate; the base 

 of the third and sixth segments transversely, and of tiie 

 fourth and fifth segments more broadly, at the sides yellow ; 



